Tie rod joint seal



Dec. 14, 1948. A. VENDITTY TIE ROD JOINT SEAL Filed Jan. 1, 1944 y n5 Z a 7 5 V Nm h t n A B.

m 7 a E a a a M M Patented Dec. 14, 1948 TIE ROD JOINT SEAL Anthony Venditty, Detroit, Mich assignor to Thompson Products, Incorporated, Cleveland, Ohio, a corporation of Ohio Application January 1, 1944, Serial No. 516,740

1 Claim. 1

This invention relates to seals for Joints such as universal Joints which will prevent the entry of water and dirt into the joint housing while allowing excess lubricant to bleed out of the housing.

Specifica ly, the invention relates to tie rod joint grease seals capable of effectively sealing the joint socket while allowing superfluous grease which might be inadvertently pressured into the socket by high pressure grease suns to escape without damaging the seal.

The invention will hereinafter be specifically described as embodied in a tie rod joint, but it should be understood that the seals of this invention are useful in many installations and therefore the invention is not limited to tie rod joint usage.

In accordance with the invention a socket member receives, in snug fitting relation over one end thereof, a seal member having a. face accommodating tilting movements. This seal member is hard enough to resist wear, but soft enough to be deformed under abnormal load. The seal member is preferably composed of synthetic rubber or other resilient plastic material. A joint member projects from the housing through the seal member and receives a metal disk thercaround which is of arcuate contour to ride on the seal member carried by the housing. The disk contour is preferably flatter than the contour of the face of the seal member on the housing so that circle line contact between the disk and seal member is obtained until the seal member is deformed under pressure whereupon the line contact is increased to area contact.

The disk member is backed up by a resilient member such as a rubber bushing or a spring for urging the disk member against the housingcarried seal member. The disk member can rotate and tilt on the housing seal member and is sealed relative to the Joint member around which it is mounted either by the rubber bushing or by a spring-urged seal member. It also has sealing contact with the housing-carried seal member.

In a modification of the invention the housingcarried seal member can be rigldified with a metal insert which prevents excessive wear of the plastic material when high pressures are encountered.

It is, then, an object of the invention to provide a dust cover for tie rod joints which effectively seals against the entry of water and dirt while allowing superfluous grease in the joint housing to escape without damaging the seal.

A further object of the invention is to provide a tie rod joint grease seal which eflectlvely seals tie rod Joint sockets from water and dirt while allowing excess grease to bleed from the socket without destruction oi the sea].

A still further object of the invention is to provide a dust cover and grease seal for universal ,ioints wherein a metal member rides on a resilient plastic material member and deforms the resilient plastic material member when subiected to increased load.

A specific object of the invention is to provide a tie rod Joint seal wherein the joint housing is provided with a molded resilient plastic material seal part snugly engaging one end thereof and wherein the joint stud is equipped with a spherical metal stamping piece for riding on the molded seal part.

A further specific object of the invention is to increase the wear resistance of molded plastic seal parts by incorporating a metal insert therein. Another object of the invention is to provide a joint accommodating universal movement wherein seal parts normally have line engagement with each other but are brought into area engagement with each under abnormal conditions.

Other and further objects of the invention will be apparent to those skilled in the art from the following detailed description 0! the annexed sheet of drawings which, by way of preferred example, illustrates two embodiments of the invention.

On the drawings:

Figure 1 is a side elevational view, with parts in vertical cross-section, of a tie rod Joint equipped with a seal in accordance with this invention.

Figure 2 is a view similar to Figure 1 but illustrating the joint and seal in tilted position.

Figure 3 is a side elevational view of the resilient deformable seal part of the seal of this invention.

Figure 4 is a fragmentary vertical cross-sectional view, with parts in elevation, of a tie rod joint equipped with a modified seal construction of this invention.

As shown on the drawings:

In Figures 1 and 2 the reference numeral l0 designates generally a tie rod .iolnt housing or socket while the reference numeral ll designates generally a stud tiltable and rotatable in the housing or socket M.

The housing III has a generally cylindrical end portion I2 which is somewhat tapered as shown, together with a laterally extending externally threaded stem portion IS. The stem I3 is adapted to be threaded into the end of a tie rod (not shown). The cylindrical and II of the housing ili provides a socket chamber II with a fragmental spherical bearing wall it at one end thereof converging to an opening ii in the top part of the housing.

The bottom of the chamber i4 is closed by means of a closure disk I! which is seated in a counterbore l3 and retained in the counterbore by means of a spun-over portion it of the housing. A coil spring 20 is bottomed on the closure disk i1 and acts on a retainer cup 2| having a top wall with a rounded depression 22 therein. The spring urges the retainer member 2| upwardly in the chamber i4 toward the opening i3.

The stud II has a rounded button-like end 23 seated in the rounded depression 22 of the retainer cup 2|. The stud I I also has a fragmental spherical head portion 24 tiltable and rotatable on the bearing wall l of the housing. A cylindrical shank portion 25 of the stud projects freely through the opening it of the housing and a frusto-conical shank portion 23 has the base thereof at the upper end of the cylindrical portion 25 and the apex thereof at the base of an externally threaded cylindrical portion 21.

A steering arm knuckle or connecting link has an eye end 23 seated on the tapered portion 26 of the stud and held in clamped relation thereon by means of a nut 29 threaded on the portion 21 oi. the stud.

Lubricant is introduced into the socket chamber it through a fitting 30 threaded into the portion l2 of the housing ii.

The top end of the housing portion i2 has a flat end face l2a surrounding the opening it and, in accordance with this invention, a relatively hard but resiliently deformable sealing member 3| has a recess 32 bottomed by an annular shoulder 33 receiving the top portion of the housing part I! with the end face |2a of the housing part bottomed on the shoulder 33 and with the side wall of the recess snugly engaging the side wall of the housing.

As shown in Figure 3 the seal part 3| has a cutout portion 34 in the side wall thereof to receive the stem i3 of the socket l3 as indicated in Figures 1 and 2 in dotted lines.

The seal member 3| has a diverging central aperture 35 therethrough adapted to continue the opening l8 of the housing part i2 and freely receive the cylindrical portion 25 of the stud The seal member 3| has a segmental spherical top wall 36 struck from a radius R centered on the axial center of the housing part i2 as shown in Figure 1. This face 33 accommodates tilting or rocking movements and is also deformable under abnormal pressures.

The seal member 3| can be conveniently molded from synthetic plastic material, such as synthetic rubber, or other grease-resisting resilient plastic, and, to increase its wearability, a stamped metal insert 31 is preferably provided in the molded piece. As shown in Figures 1 and 2, this insert 31 has an upturned flange rigidifying the hole 35 defining portion of the seal piece together with a downturned .flange rigidifying the recess 32 defining portion of the piece. The insert 31 is completely covered with deformable plastic material however.

The piece 3| can be formed by molding the plastic material around the stamping 31.

As shown in Figures 1 and 2, a metal washer fill of segmental spherical contour has a central opening 4| therethrough freely receiving the cylindrical portion 25 of the stud. The washer 43 is struck from a radius longer than the radius B. so that the concave under face of the washer only has a circle line contact with the seal face 36 under normal conditions.

A deformable bushing 42 such as synthetic rubber or the like is sealingly disposed around the cylindrical portion of the stud and held under compression between the eye member 23 and the washer iii to urge the washer into sealing contact with the surface 33 of the seal piece 3|. At the same time the bushing 42 seals the hole ii in the washer to prevent leakage through this hole.

As indicated in Figure l, the washer M will normally have a circle line contact with the face 33 of the seal piece 3| close to the hole in the seal piece. However. when the stud ii and eye 28 thereon is tilted, the rubber bushing 42 is loaded on one side more than on the other side thereof and exerts more pressure on this highly loaded side against the washer lil causing the washer to deform the sealing face 33 of the seal piece 3| into full conformity with the arcuate under face of the washer and therebil change the line contact into an area contact between the washer and seal piece 3 As also indicated in Figure 2, the insert 31 holds the seal piece 3| snugly on the housing part l2 even when it is deformed by the washer 4|! being pushed thereover in the direction of tilt.

The washer has a flatter contour than the face 33 of the seal piece 3| so that greater tilting angles of the stud can be used without striking the washer on the stem l3. At the same time the washer has full circle line contact with the seal piece 3| which is sufficient to seal the socket chamber II.

In the event that the chamber i4 is filled with an excessive amount of grease, this grease can work up between the stud head 24 and bearing wall It through the opening l8 and hole 35 of the seal piece 3| where it will exert pressure on the washer l0 tending to raise the washer off of the face 36 whenever the grease pressure exceeds the pressure exerted on the washer by the bushing 42. As a result excess grease can bleed out of the housing without damaging the seal. Of course, as soon as pressure on the outer face of the washer exceeds the pressure inside of the housing, the washer will have sealing contact with the seal piece 3|.

In the embodiment shown in Figure 4 of the drawings, parts have been marked with the same reference numerals, but the seal part 3| is not equipped with the metal insert 31 of Figures 1 and 2, and is simply a one-piece molded plastic ring seated on the top of the housing part l2 and providing the rocking surface 36 for the metal seal washer 40.

The rubber bushing 42 of Figures 1 and 2, however, has been replaced with a coiled spring and a thin. flexible washer 5| composed of leather, synthetic plastic material. or the like. The washer 5| snugly engages the cylindrical part 25 of the stud l and seals the hole 4| in the washer All. The spring 50 acts through the washer ii on the washer 43 for maintaining sealing engagement between the concave under face of the washer 40 and the convex rocking face 36 of the seal piece 3|.

The seal of Figure 4 operates in the same manner as the seal of Figures 1 and 2 but the spring 5|) can compress to accommodate relative tilting between the washer 40 and eye piece 28 so that the washer 30 does not present a greatly increased pressure load on the seal piece 3| such as is illustrated in Figure 2. The washer ll thereby maintains more of a circle line contact with the seal piece ll of Figure 4 during all tilting positions of the stud but nevertheless the piece 31 is deformable under abnormal load to have area contact with the washer 49. Since the seal piece 3| of Figure 4 is not subjected to the greater wearing loads as when the washer I is backed by a solid bushing such as 42 illustrated in Figure 2, the metal insert need not be used. course, if desired, the seal piece II of Figure 4 could be used in the embodiment of Figure l and 2, while the seal piece 3| of the embodiment of Figures 1 and 2 could be used in the embodiment of Figure 4.

From the above descriptions it will be understood that the invention now provides a dust cap and grease seal for tie rod joints which is simple. inexpensive, and at the same time eifectlve to exclude dirt and water from the joint socket while not being damaged by excess grease pressure in the socket. The relatively moving seal parts are normally in line contact which closely approaches area contact and actually do have area contact under abnormal loads because at least one of the seal parts is resiliently deformable.

It will, of course, be understood that various details of construction may be varied through a wide range without departing from the principles of this invention and it is, therefore, not the purpose to limit the patent granted hereon REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,902,667 Sanders Mar. 21, 1933 2,083,719 Kuil et a1. June 15, 1937 2,111,200 Amourelle Mar. 15, 1938 2,157,401 Craver May 9, 1939 2,206,972 Niles July 9, 1940 2,272,650 Von Veh Feb. 10, 1942 2,301,346 Venditty Nov. 10, 1942 2,364,176 Waldron Dec. 5, 1944 FOREIGN PATENTS Number Country Date 121,867 Great Britain Jan. 9, 1919 540,372 Great Britain Oct. 15, 1941 

